Starter Motor Rebuild - Does this look knackered?

[mintyhit]

Afternoon all

I am finally starting to get to the bottom of all the starting woes I have been having over the last year - I managed, with some perseverance, to get the electrical side of the starter motor off without having to remove the engine casing.

This is what I found:

Annihilated bushes?

http://farm7.static.flickr.com/6058/5905410783_1dc42b2018.jpg

http://farm6.static.flickr.com/5039/5905974546_cb934ed197.jpg

Slightly pulverized armature?

http://farm6.static.flickr.com/5199/5905416763_92bcf2e410.jpg

I think this explains a lot and it is little wonder that I keep getting through batteries trying to force a starter in this condition to spin. Now the question is, can it be rebuilt\repaired without removing it?

I know I can change the bushes easily enough but I am concerned that the armature will chew the new ones up due to the the fact it looks damaged. It is hard to tell from the picture but there are 3 - 4 points that look a bit torn up.

Any thoughts, can this be salvaged? I really don't fancy taking the flywheel\engine casing off but if I have to I have to I guess.

Cheers all

[Stafford]

The commutator looks a bit stuffed fella, get the allen keys out and get stripping.
Not had one done but could be repairable, certainly new brushes out there but the com might need a very light skim in a lathe or polish?

[Rally]

Check out with Cairojay, I suggested somewhere to him to get one done. He should have it back by now and can let you know his findings of them. They recon any starter or alternator.

[Pomp1]

New bushes from Ducati are under 20 quid.Commutator is strange, as it seems like the bushes got stuck to it at some point. Word of advice on the bushes: there's a plastic insulation where the posi current for for a through. They snap easily as you secure the rod.

[PaulR]

My commutator looked a bit like that - I changed the brushes (and broke that insulating piece the first time) and it turned over about 5 times before dying. Well done for getting the cap off without taking the whole motor out, but if the commutator is badly damaged it may just knacker the new brushes straight away. There's a pic of mine on a starter motor thread from a few weeks back. Good luck!

[slob]

Why the reluctance to take the cover off James?
Apart from the cost of a tube of 3 bond it's easy.
If you lay the bike carefully on the r/h side it can be done without even draining the oil, we've done it several times in a race paddock, laying bikes on old tyres.

[Dookbob]

The starter motor looks no worse than a few I have repaired, as Stafford says, new brushes, and skim the comutater. Quick check with a multimeter after skimming will tell you if its ok or not, if not then it,s Ebay for a new old one that dont look quite as rough as yours. Stop struggling with it , get the cover off and do it proper, and when you buy your new BRUSHES, dont ask for BUSHES.

[mintyhit]

Cheers for all the advice guys!

I went out again this morning to take a closer look at the communicator and it is definitely more chewed up then I realised. There are scores and gouges on the other side that are pretty deep. I imagine a few mm of material would need to be skimmed to get it smooth again – I don’t suppose anyone knows if there is a skimming limit for these components?

My reluctance to take engine covers off is generally because the only place I have to work is my front patio. It certainly isn’t the cleanest environment to be exposing the innards of an engine to… not to mention the inevitable oil spills that will result - I also haven't got many old tyres lying around Rob, if I did that might be the last straw with my housemates. :)

I’ll get cracking though and just be careful – I think I might opt for a second hand starter if I can source one. I’d rather just to a straight swap than mess about sending it to an engineering shop that may or may not make a pigs ear of skimming it… plus I don’t think my constitution can take taking the bus to work for much longer! :)

[mintyhit]

Oh, also does anyone know if it is possible to change the starter without removing the clutch? I thought I read a post recommending a very long alan socket but I can't find it.

Also, I found this on ebay:
http://cgi.ebay.co.uk/Ducati-starter-motor-new-748-750-851-900-904-916-996-/230605676518?pt=UK_Motorcycle_Parts&hash=item35b12b5fe6

£100 with a year’s warranty and free postage. Electrex are fairly reputable as well for RR replacements... I might just bite the bullet - it will cost £21 + postage for a brush kit + however much for a skim + a lot of messing about to fix my old one.

[slob]

Assume you mean the starter clutch, not the dry 'clutch clutch'? which you don't need to touch.
The starter motor is held on by three bolts, two are readily accessible (one inside the case and one outside) the third you need to turn the starter gear and access through one of the holes in the gear itself.
No need to touch the starter clutch either.

http://www.ukmonster.co.uk/monster/attachment.php?attachmentid=15289&stc=1&d=1309955064

[mintyhit]

Ahh.. I actually meant the flywheel... not the clutch – although the starter clutch is relevant as well I guess.

So I don't have to remove the flywheel to remove the start motor - it isn't all that clear in the workshop guide.

Well it doesn’t sound all that difficult then, perhaps I’ll take a wheel off my car and go for the lay the bike down approch as Rob suggested.

[slob]

the starter clutch is in the back of the flywheel, that can all stay put, you just need to rotate it (plugs out before you start helps!) make sure you leave enough space under the bike to actually pull the starter motor off when you're lying the bike down.

sorry for the low quality photo but you can just make out 3 of the 4 holes in the idler gear that allow you to access the elusive allen bolt.

http://www.ukmonster.co.uk/monster/attachment.php?attachmentid=15290&stc=1&d=1309956946

...and get some threadlock before you start, you'll want that for reassembly.

[mintyhit]

Ahh, that’s made things much clearer, cheers.

My new starter should turn up in a couple of days so I’ll post up how I get on.

...oddly, I recognise that green floor! :)

[mintyhit]

Hey All,

So I just got back from holiday to find one of these sitting on my desk:

http://farm7.static.flickr.com/6143/5933720472_ce89002bdb_m.jpg

I bought it from eBay for £99 Inc postage and it arrived the next day – not bad I thought – it is an Electrex World unit with a years guarantee.

Going to have a go at fitting it tonight without draining the oil if I can (only changed it a couple of months ago).

Does anyone know if I will do any damage by gently laying the bike down on its side on just my R&G cash bobbins? - I have one of my front wheel and one of my frame.

Cheers
James

[mintyhit]

Well, the answer to my last question is yes, the crash bobbins are perfect for leaning the bike over and allowing access but unfortunately now I have another problem – the new starter rather disappointingly outright refuses to spin – I just get a loud click from the solenoid.

Fitting the new motor indeed wasn’t that hard, it took me a while to make a puller fabricated out of a bit of aluminium from an old toy scooter but now I am wondering if I might have missed something.

I have a brand new and fully charged Motobatt battery and I tested the battery on an old car starter with a pair of jump leads and that spins ok.

I wondered if it might be a wiring fault so I tried jumping the starter directly from the battery (both positive and negative to the casing) with my jump leads and all I get is a big spark but still no spin.

I wish I would have tested it before I installed it but I didn’t but it seems improbable that a new starter would be duff.

Has anyone got any theories before I got taking the casing off again? It feels to me like the starter is just shorting, hence the bit spark and discoloration on the terminal when I connect it straight to the battery.

Hmmm… :(

[Stafford]

When you had the casing off did you spin the flywheel to check the engagement of the gears for any tight spots? It will only spin one way cos of the sprag clutch.
From your fist picture the commutator seemed burnt quite badly in one spot, is this the case? If yes you may have another issue when the starter is in a particular spot. Had a similar mark on an Audi widow motor once as it always stopped in the same place. Just thoughts.

[mintyhit]

I can’t say I really checked properly to be honest - I could turn the idler gear and the engine over.

I’ve just read about a dozen threads regarding starting problems and it does seem that the sprag clutch on the 916 engine can fail although I would expect the starter still to spin just not engage rather then doing nothing?

Is it possible the sprag has disintegrated and jammed up the gears I wonder?

I am going to whip the case off again today – I am thinking that if I remove the starter and test it again on the battery I’ll be able to narrow it down to the sprag if it spins.

… then I’ll just have to borrow a clutch tool, spend another hundred squid or so on a new clutch and put it all back together again.

Ar$e! :(

[Pomp1]

As I've discovered you could assemble the outer casing of the motor the wrong way round, which it makes it spin the wrong way..

[gary tompkins]

Should be able to prove that by testing it off the engine

[mintyhit]

I've just tested the starter off the engine - dead! It must have an internal short as it just sparks viciously without spinning.

Arggg... just my luck. Oh well, now we can see how good Electrex World's return policy is.

Moral of the story - just because a component is new - don't assume it works. :)

[sbhumphrey]

I was about to buy a new starter motor from Electrex World, I guess I will wait and see how you get on.

[mintyhit]

I've just had an e-mail back from them confirming that the unit is at fault. I guess it is bound to happen every once in a while.

They are sending me a new one and it should be with me tomorrow. Their customer service has been excellent so far.

Obviously I can’t comment on quality of the starter yet but it looks identical to the original - they are cheaper on the eBay store then on their own website as well.

[Stafford]

I've just had an e-mail back from them confirming that the unit is at fault. I guess it is bound to happen every once in a while.


Blimey, if you didn't have bad luck you'd have no luck at all.

[mintyhit]

Haha… it could be so much worse - i'll take a faulty starter over a FUBR sprag clutch any day.

I'm just looking forward to finally solving all my starting and running problems and being able to trust the bike enough to go on long runs. :)

[mintyhit]

Hmmm… this is turning into a right saga now.

So I got a new starter motor delivered and an e-mail telling me the first one they sent me was faulty, ok great. I hooked it up to a battery and it works, again - great. I spend 2 hours fitting it and confidently attempt to start the bike.

*click* - bollocks.

Ok so perhaps the starter wasn’t at fault then after all - or perhaps I accidently burnt out the last one trying to start the bike with a jammed sprag (oops).

So the battery is brand new and fully charged, the starter is new – perhaps it has to the be the sprag after all - although the starter gear will rotate both ways, by hand one way and the other with some gentle levering so that would suggest it isn’t jammed.

...So it looks like my next task is to take the flywheel off and have a look – I’ll report back when I do.

Also if anyone has the flywheel holding tool in london I could borrow that would be a massive help. :)
http://www.ukmonster.co.uk/monster/showthread.php?t=41944

[mintyhit]

FIXED!

Not as bad a job as I first thought.

I welded up a DIY tool to hold the flywheel in place using an old valve spring compressor I had lying around - I just didn’t feel that comfortable using a 2p and it gave me a chance to weld something. My air impact gun made pretty short work of removing the flywheel nut and I found that my sprag was indeed looking a bit on the worn side.

I changed the sprag for a nice low mileage replacement I got for £90, gave everything a good clean with the airgun, changed the oil and the filter (wasn’t due but I figured I might as well) and bolted her all back together again.

The result: Blimey, I had forgotten how they are supposed to start - just a gentle stroke of the starter button and BRUUUMMMM… as apposed to *spin* *spin* *spin* *spin* cough *spin* *spin* splutter *spin* *spin* BRRU-COUGH-DIE *spin* *spin* FLAT BATTERY. I am still not sure why it wouldn’t spin before but changing the sprag has fixed everything and the starter is fine.

So I now have a completely new starting circuit – what a difference. I totally recommend Electrex World for a replcment starter. Just make sure you have a small pair of circlip pliers for swapping the gear over from your old starter – I gave myself multiple stab wounds trying to do it with a screwdriver.

Hopefully this will be the end of all my starting woes. :)

[sbhumphrey]

Electrex World it is then. Thanks for the update

[mintyhit]

No problem - check their eBay listings, they seem are cheaper than the web price and you still get the warranty plus PayPal protection.

James